Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

TL;DR

This study evaluates the accuracy of various hadronic interaction models in Geant4 by comparing their predictions to detailed data from a highly granular silicon-tungsten calorimeter using 350,000 pion events at 2-10 GeV.

Contribution

It provides a comprehensive comparison of Geant4 physics models against high-resolution calorimeter data, highlighting areas of agreement and discrepancy in hadronic interaction simulations.

Findings

Monte Carlo models are within 20% of experimental data

Good overall agreement in many observables

Largest discrepancies in energy distribution profiles

Abstract

The CALICE collaboration has published a detailed study of hadronic interactions using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter (Si-W ECAL). Approximately 350,000 selected negative pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the Geant4 simulation tool kit are compared to this data. A reasonable overall description of the data is observed; the Monte Carlo predictions are within 20 % of the data, and for many observables much closer. The largest quantitative discrepancies are found in the longitudinal and transverse distributions of the reconstructed energy. Based on the good control of the data set and general observables, the next step is to achieve a deeper understanding of hadronic interactions by studying the interaction zone and by reconstructing secondaries that emerge from the hadronic interaction in the Si-W ECAL.